Process for preparing higher hydridosilanes

ABSTRACT

Process for preparing higher hydridosilanes of the general formula H—(SiH 2 ) n —H where n≧2, in which—one or more lower hydridosilanes—hydrogen, and—one or more transition metal compounds comprising elements of transition group VIII of the Periodic Table and the lanthanides are reacted at a pressure of more than 5 bar absolute, subsequently depressurized and the higher hydridosilanes are separated off from the reaction mixture obtained.

The invention relates to a process for preparing higher hydridosilanesby means of a dehydropolymerization reaction of lower hydridosilanes.The invention further relates to the use of the higher hydridosilanes asstarting material for the preparation of silicon.

The dehydropolymerization of lower hydridosilanes to form higherhydridosilanes is a promising route to silicon. For the purposes of theinvention, hydridosilanes are compounds which contain only silicon andhydrogen atoms and have a linear, branched or cyclic structurecontaining Si—H bonds. Examples which may be mentioned are monosilane,disilane, trisilane, cyclopentasilane.

U.S. Pat. No. 4,965,386 discloses a process in which hydridiccyclopentadienyl complexes of scandium, yttrium or the rare earths areused as catalyst. It is found in practice that this is a suitableprocess for preparing alkylsilanes and arylsilanes, i.e. compounds whichhave at least one carbon-silicon bond. In the case of higherhydridosilanes, on the other hand, this process does not giveeconomically acceptable yields.

The same is found for the process disclosed in U.S. Pat. No. 5,252,766,in which alkylsilanes and arylsilanes are converted in the presence ofcyclopentadienyl complexes of the lanthanides into the correspondingpolyalkylsilanes or polyarylsilanes. In contrast, the use of lowerhydridosilanes does not lead to appreciable amounts of the desiredhigher hydridosilanes. Rather, undesirable, polymeric solids which canbe spontaneously flammable are formed.

JP 02-184513 discloses a process in which the products are disilane,trisilane or a mixture of the two is obtained from monosilane by meansof a transition metal-catalyzed reaction. The process does not lead tothe formation of higher silanes.

U.S. Pat. No. 6,027,705 discloses a thermal process for preparing higherhydridosilanes from monosilane or lower hydridosilanes. The process issaid to lead to higher hydridosilanes at temperatures above roomtemperature. In practice, temperatures of more than 300° C. arenecessary to achieve appreciable conversions. A disadvantage of thisprocess is the high thermal stress which promotes secondary anddecomposition reactions.

Various processes for preparing higher hydridosilanes, which are basedon the dehydropolymerization of lower hydridosilanes, are thus known.The reaction is carried out either thermally or in the presence oftransition metal catalysts. However, the known processes are notsuitable for the economical preparation of the products. Spontaneouslyflammable by-products which make the work-up difficult and contaminatethe products are often formed.

It was therefore an object of the present invention to provide a processwhich allows the economical preparation of higher hydridosilanes andlargely avoids the disadvantages of the prior art.

The invention provides a process for preparing higher hydridosilanes ofthe general formula H—(SiH₂)_(n)—H where n≧2, in which

-   -   one or more lower hydridosilanes    -   hydrogen, and    -   one or more transition metal compounds comprising elements of        transition group VIII of the Periodic Table and the lanthanides        are reacted at a pressure of more than 5 bar absolute,        subsequently depressurized and the higher hydridosilanes are        separated off from the reaction mixture obtained.

For the purposes of the invention, lower hydridosilanes encompassmonosilane (SiH₄) or mixtures containing monosilane together withproportions of higher hydridosilanes. The proportion of higherhydridosilanes can be up to 60 mol %, in general from 5 to 20 mol %,based on the mixture. For availability reasons, preference is given tousing monosilane.

Higher hydridosilanes encompass, for the purposes of the invention,mixtures of hydridosilanes of the formula H—(SiH₂)_(n)—H, where n≧2. Themixtures usually contain higher hydridosilanes where 2≦n≦20, butdepending on the reaction conditions, higher hydridosilanes in whichn>20 can also be obtained. Preference is given to a mixture where2≦n≦20, with particular preference being given to a mixture where2≦n≦10. Such a mixture generally contains Si₂H₆, Si₃H₈, n-Si₄H₁₀,n-Si₅H₁₂, n-Si₆H₁₄ as main components, possibly together with n-Si₇H₁₆,n-Si₈H₁₈, n-Si₉H₂₀ and n-Si₁₀H₂₂ as secondary components.

Further secondary constituents can be branched hydridosilanes, forexample, i-Si₆H₁₄, or cyclic hydridosilanes, for examplecyclopentahydridosilane (cyclo-Si₅H₁₀). The total proportion of thesecondary constituents can be up to a maximum of 10% by weight,generally up to a maximum of 5% by weight, preferably up to a maximum of2% by weight, in each case based on the sum of the hydridosilanes andthe secondary components. These values are based on estimates sincecalibration substances are not available for all secondary constituents.

A further essential starting material in the process of the invention ishydrogen. Hydrogen can be introduced into the reaction vessel eitherseparately or together with the lower hydridosilanes. It has been foundthat the presence of hydrogen leads to higher yields of higherhydridosilanes and reduces or completely prevents the formation ofsolid. The formation of solid is undesirable, inter alia, because itoften ignites spontaneously during the work-up of the reaction mixtureand thus represents a considerable safety risk. The precise structure ofthis solid is not yet known.

The proportion of hydrogen is initially not limited. It depends on thestarting materials, lower hydridosilanes and catalysts, and on thereaction conditions, pressure and temperature. The partial pressure ofhydrogen is 5-200% of the pressure of the hydridosilanes used. Ingeneral, the proportion of hydrogen is selected so that the partialpressure of hydrogen corresponds to at least 5% of the total pressure.Preference is given to a range from 5% to 80%, particularly preferablyto a range from 15% to 50%.

Furthermore, it is also possible to use inert gases such as nitrogen,argon or helium for diluting the reaction mixture.

A further essential constituent of the process of the invention is oneor more transition meal compounds comprising elements of transitiongroup VIII of the Periodic Table, namely Fe, Co, Ni, Ru, Rh, Pd, Re, Os,Ir, Pt, and the lanthanides, namely Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy,Ho, Er, Tm, Yb, Lu.

The transition metal compounds are generally used in the form of aprecursor. The ligand is added separately, so that the catalyst isformed in situ. However, it is also possible to use commerciallyavailable catalysts.

Suitable precursors which are used are, for example, metal salts such aschlorides, bromides, iodides, fluorides, acetates, acetylacetonates,sulphates, sulphonates, nitrates, phosphates,trifluoromethane-sulphonates, alcoxides, hexafluorophosphates,carbonyls, carboxylates or metal precursors in which M=Fe, Co, Ni, Ru,Rh, Pd, Re, Os, Ir, Pt, and the lanthanides, namely Ce, Pr, Nd, Pm, Sm,Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu.

M(COD)_(x) where COD=1,5-cyclooctadiene,

M(C₈H₁₂)(C₅H₇O₂), where C₈H₁₂=1,5-cyclooctadiene and

C₅H₇O₂=acetylacetonato

M(CO)x(C₅H₇O₂), where C₅H₇O₂=acetylacetonato

metal carbonyls, MCl(CO)x, [MClx(CO)y]₂, M(allyl)Cl, MCl(C₇H₈), whereC₇H₈=norbornadiene

M(C₈H₁₂)₂(BF₄)_(x), where C₈H₁₂=1,5-cyclooctadiene

M(C₇H₈)₂(BF₄)_(x), where C₇H₈=norbornadiene

[M(1,5-C₈H₁₂)Cl]₂, where 1,5-C₈H₁₂=1,5-cyclooctadiene

M(Cp)₂, where Cp=unsubstituted or alkyl-substituted cyclopentadienyl

M(C₄H₇)₂(C₈H₁₂), where C₄H₇=methylallyl and C₈H₁₂=1,5-cyclooctadiene,[M(O₂CCH₃)x]₂ where (O₂CCH₃)=acetate, where M is in each case thetransition metal. x depends on the valency of the transition metal.

The ligands of the transition metal compounds can preferably be halogen,hydrogen, alkyl, aryl, alkylsilanes, arylsilanes, olefin, alkylcarboxyl,arylcarboxyl, acetylacetonatoalkoxyl, aryloxy, alkylthio, arylthio,substituted or unsubstituted cyclopentadienyl, cyanoalkane, aromaticcyano compounds, CN, CO, NO, alkylamine, arylamines, pyridine,alkylphosphine, arylphosphine, alkylarylphosphine, alkyl phosphites,aryl phosphites, alkylstibane, arylstibane, alkylarylstibane,alkylarsane, arylarsane or alkylarylarsane.

Particularly preferred ligands are: bipyridyl, unsubstituted orsubstituted cyclopentadienyl, cyclooctadiene, CN, CO, alkylphosphine,arylphosphines, alkyl or aryl phosphites, alkylarylphosphine, bidentatephosphine ligands having bridging heterocycles or bridging arylradicals, a heteroatom-containing ligand, particularly preferably aphosphorus-containing ligand, which has the ability to produceatropisomerism in respect of two aryl or hetaryl systems,alkyldiphosphine R²R¹—P(CH_(y))_(x)P—R³R⁴ where R¹, R², R³ and R⁴ areeach, independently of one another alkyl or aryl and x=1-10 and y=0, 1or 2, R²R¹—P—CR⁵R⁶(CR⁷R⁸)x-CR⁹R¹⁰—P—R³R⁴ where R¹, R², R³, R⁴, R⁵, R⁶,R⁷, R⁸, R⁹, R¹⁰ are each, independently of one another H, alkyl or aryland x=1-10; R¹—C≡C—R², where R¹ and R² are each, independently of oneanother, alkylphosphines or arylphosphines.

As commercially available catalysts, it is possible to use, for example,bis(cyclopentadienyl)nickel (nickelocene), bis(cyclopentadienyl)titaniumdichloride, bis(cyclopentadienyl)zirconium dichloride (zirconocenedichloride), 1,1′-bis(diphenylphosphino)ferrocene,bis(triphenylphosphine)nickel(II)chloride,carbonyl(dihydrido)tris(triphenylphosphine) ruthenium (II),carbonylchlorohydridotris(triphenylphosphine) ruthenium (II),chlorotris(triphenylphosphine)rhodium(I), (Wilkinson catalyst),dimethylbis(t-butylcyclopentadienyl)zirconium,bis(triphenylphosphine)nickel dicarbonyl.

For example, it is possible to use the following compounds:Ni[Ph₂P(CH₂)₃PPh₂]Me₂, Ni[Ph₂P(CH₂)₃PPh₂]Cl₂, Ni(PPh₃)₂Me₂,Ni(PPh₃)₂Cl₂, Ni(PMe₂Ph)₂Me₂, Ni(COD)₂, NiEt₂, Ni(CNMe)(CO)₃, Ni(Cp)Cl₂,Ni(Cp)I₂, Ni(Cp)NO, Ni(CF₃C≡CCF₃)(CO)₂, Ni(Cp)(CN)₂, Ni(Cp)(CO)I,Ni(πCH₂═CHCH₂₎₂, Ni(Cp)(CO)CF₃, Ni(NCCH═CHCN)₂, Ni(Cp)(CO)C₂F₅,Ni(cyclooctatetraen), Ni(Cp)(πCH═CHCH₂), Ni(EtNC)₂(CN)₂, Ni(MeNC)₄,Ni(Cp)(PPh₃)Cl, Ni(CH₂═CH₂)(PEt₃)₂, Ni(Cp)(PPh₃)Et,Ni[Ph₂P(CH₂)₂PPh₂]BrMe, Ni[PhP(CH₂)₃PPh₂]BrMe, Ni(CH2=cH2)(PPh₃)₂,Ni(AN)(PPh₃), (πCH₂═CHCH₂)NiCl)₂, (πCH₂═CHCH₂NiBr)₂, [Ni(Cp)(CO)]₂,[Ni(Cp)]₂HC≡CH, [Ni(Cp)₂HC≡CCH₃, [Ni(Cp)]₂CH₃C≡CCH₃, Ni(dip)Cl₂,Ni(dip)Br₂, Ni(dip)ClMe, Ni(dip)Me₂, Ni(dip)Et₂, NiCp₂, Ni(CO)₄,Ni(AN)₂, Ni(acac)₂, Ni[Ph₂P(CH₂)₃PPh₂PhClMe, Ni[Ph₂P(CH₂)₃PPh₂]Br₂,Ni[Ph₂P(CH₂)₃PPh₂]Et₂, Ni[Ph₂P(CH₂)₃PPh₂]H₂, Ni(PPh₃)₂ClMe,Ni(PPh₃)₂HMe, Co(PPh₃)₂Me₂, Co(PPh₃)₂Cl₂, CO₂(CO)₈,Co[Ph₂P(CH₂)₂PPh₂]Me₂, Co(PPh₃)₂Br₂, Co(PPh₃)₂BrMe, Co(PPh₃)₂ClMe,Co(PPh₃)₂Et₂, Co[Ph₂P(CH₂)₃PPh₂]Me₂, Co[Ph₂P(CH₂PPh₂]ClMe,Co[Ph₂P(CH₂)₃PPh₂]Cl₂, Co[Ph₂P(CH₂)₃PPh₂]ClMe, Co(CO)₄Me, Co(Cp)Cl₂,Co(Cp)Me₂, Co(πCH₂═CHCH₂)(CO)₃, Co(Cp)(CO)₂, Co(Cp)₂, [Co(Cp₂]Br₃,[Co(Cp)₂]Cl, Co(PPh₃)(CO)₃Me, Co(PPh₃)₂H₂, Co(PPh₃)₂Br₂, Pd(PPh₃)₂Me₂,Pd(PPh₃)₂Cl₂, Pd(PPh₃)₂ClMe, Pd(PPh₃)₂H₂, Pd(PPh₃)₂Et₂, Pd(PPh₃)₂Br₂,Pd(PPh₃)₂BrMe, Pd(PPh₃)₂I₂, Pd(Cp)Br, Pd(Cp)Cl, Pd(AN)₂Cl₂,Pd(πCH₂═CHCH₂)₂, Pd(πCH₂═CHCH₂)₂Cl₂, Pd(Cp)(πCH₂═CHCH₂), Pd(COD)Cl₂,Pd(COD)Me₂, Pd(COD)ClMe, Pd(dip)Me₂, Pd(PEt₃)₂CNMe, Pd(Pet₃)₂Me₂,Pd(pMeOC₆H₄)₂Br₂, Pd[Ph₂P(CH₂)₂PPh₂]Me₂, Pd[Ph₂P(CH₂)₃PPh₂]Me₂,[Pd(πCH₂═CHCH₂)Cl]₂, [Pd(πCH₂═CHCH₂)Br]₂, Ru(PPh₃)₃Me₂, Ru(PPh₃)₃Cl,Ru(PPh₃)₃ClMe, Ru(PPh₃)₃Br₂, RU(PPh₃)₃Et₂, RU(PPh₃)₂, CIMe₂,Ru(PPh₃)₃H₂, Ru(Cp)(CO)₂H, Ru(COD)Cl₂, Ru(Cp)(CO)₂Me, RU(COD) Br₂,RU(MeNC)₄Cl₂, Ru(Cp)(CO)₂Et, Ru(Cp)₂, Ru[Ph₂P(CH₂)₂PPh₂]₂ClMe,Ru[Ph₂P(CH₂)₃PPh₂]₂ClMe, Ru[Ph₂P(CH₂)₂PPh₂]₂ClPh, Ru(EtNC)₄Cl₂,Ru(EtNC)₄Br₂, Ru(EtNC)₄Me₂, Ru(EtNC)₄Et₂, Ru[Ph₂P(CH₂)₃PPh₂]₂BrMe,Ru[Ph₂P(CH₂)₂PPh₂]₂HMe, [Ru(Cp)(CO)₂]₂, Ir(PPh₃)₃(CO)Me, Ir(PPh₃)₃(CO)H,Ir(Cp)(CO)₂, Ir(Cp)₂Br₃, Ir(PPh₃)₃Me₂, Ir (PPh₃)₃Cl₂, Ir(PPh₃)₃ClMe,Ir(PPh₃)₃H₂, Ir(Ph₂P(CH₂)₂PPh₂]Me₂, Ir[Ph₂P(CH₂)₂PPh₂](CO)Me,Ir(PPh₃)₂(CO)MeClI, Ir(πCH₂═CHCH₂)(PPh₃)₂Cl₂, Ir[p-CH₃C₄H₆NC)₄Cl,Ir(acac)(COD).

In these formulae, COD=cyclooctadiene; Cp=cyclopentadienyl;dip=bipyridyl, Ph=phenyl, AN=acrylonitrile, acac=acetylacetonate;Py=pyridine; Me=methyl, Et=ethyl; Bu=butyl.

These transition metal compounds serve as catalysts. They can be usedeither as heterogeneous catalyst, if appropriate applied to a support,or as homogeneous catalyst dissolved in the reaction mixture.

The catalyst concentration can be from 0.0001 to 1 mol/l. A range from0.001 to 0.1 mol/l can be preferred.

The best results are obtained using homogeneous catalysts. In this case,the transition metal compounds themselves can be added to the reactionmixture or the transition metal compounds are formed only in thereaction mixture by adding a transition metal compound, for example, anacetate, and a ligand separately to the reaction mixture.

In the second embodiment, a molar excess of the ligand is generallyused. Here, the systems Bis(1,5-cyclooctadiene)nickel(0),1,2-bis(diphenylphosphino)ethane; Bis(1,5-cyclooctadiene)nickel(0),trans-1,2-bis(diphenylphosphino)ethylene; Rhodium(II) acetate dimer,2,2′-bis(diphenylphosphino)-1,1′-binaphthyl;

can be particularly useful.

The process of the invention is carried out at a pressure of at least 5bar absolute. Preference is given to a range from 20 to 200 barabsolute. Below 20 bar absolute, the conversions are often notsatisfactory, while above 200 bar absolute the outlay required to meetthe demands on the materials is not justified.

The temperature at which the process of the invention is carried out isnot critical. In general, the process can be carried out at temperaturesof from −50° C. to 200° C. Preference is given to a range from 0° C. to120° C. and particular preference is given to a range from 20° C. to 80°C.

The reaction time can range from a few hours to a number of days. Theproportion of higher silanes increases with the reaction time.

The process of the invention can also be carried out in the presence ofa solvent. Suitable solvents are in principle all solvents which reactneither with the starting materials nor with the products and, if ahomogeneous catalyst is used, dissolve this. Examples are aliphatic andaromatic hydrocarbons, for example, benzene or toluene, ethers such asdialkyl ethers, furans or dioxanes, and also dimethylformamide, ethylacetate or butyl acetate.

The higher hydridosilanes can be separated off from the reaction mixtureby the methods known to those skilled in the art. Thus, for example,solvent or unreacted starting material, for example, monosilane, can beseparated off by distillation. It is also possible to use adsorptiveprocesses.

The invention further provides the use of the higher hydridosilaneswhich can be obtained by the process according to the invention forproducing silicon.

The invention further provides for the use of the higher hydridosilaneswhich can be obtained by the process of the invention for producing acharge-transporting constituent in optoelectronic and electroniccomponents.

EXAMPLES

Catalyst solution: transition metal compound and a 1.1-fold molar excessof ligand are weighed out under protective gas (argon) and dissolved in30 ml of dried toluene at room temperature.

The catalyst solution is placed in a stainless steel autoclave which isequipped with a glass liner, thermocouple, pressure sensor, liquidsampling point, gas inlet and gas outlet and has been made inert. Anappropriate amount of monosilane is introduced into the autoclave viathe gas inlet. The reactor is subsequently heated to the desiredtemperature and the stirrer is started (700 rpm). After a reaction timeof 1 h, 20 h and 67 h, a liquid sample is taken and analyzed by gaschromatography.

Table 1 shows the starting materials, amounts of starting materials andreaction temperatures.

Table 2 shows the yields, in GC % by area, of the higher hydridosilanesobtained.

Comparative examples 15 and 16 are carried out analogously but withoutusing hydrogen. Here, no higher hydridosilanes but only spontaneouslyflammable solids are formed.

TABLE 1 Starting materials and amounts of starting materials p_(SiH4)p_(H2) T Ex. mg bar bar ° C. According to the invention 1Bis(1,5-cyclooctadiene)nickel(0) 6.30 80 20 401,2-bis(diphenylphosphino)ethane 15.03 2Bis(1,5-cyclooctadiene)nickel(0) 6.09 80 20 40 trans-1,2- 10.00bis(diphenylphosphino)ethylene 3 Rhodium(II) acetate dimer, 10.12 67 2040 (±)-2,2′-bis(diphenylphosphino)-1,1′- 43.48 binaphthyl 4 Rhodium(II)acetate dimer, 11.18 67 20 40 (±)-2,2′-bis(diphenylphosphino)-1,1′-34.75 binaphthyl 5 Rhodium(II) acetate dimer, 10.84 67 20 40(±)-2,2′-bis(diphenylphosphino)-1,1′- 32.9 binaphthyl 6 Rhodium(II)acetate dimer, 11.67 67 30 40 (±)-2,2′-bis(diphenylphosphino)-1,1′-36.28 binaphthyl 7 Rhodium(II) acetate dimer, 10.51 67 30 40(±)-2,2′-bis(diphenylphosphino)-1,1′- 33.38 binaphthyl 8 Rhodium(II)acetate dimer, 11.45 65 5 40 (±)-2,2′-bis(diphenylphosphino)-1,1′- 33.04binaphthyl 9 Nickel(II) acetylacetonate* 6.65 60 20 40Tricyclohexylphosphine 30.38 10 Nickel(II) acetylacetonate* 6 60 20 40[Tris(trimethylsilyl)]phosphine 27.51 11 Nickel(II) acetylacetonate*7.23 60 20 40 Triphenylphosphine 38.67 12 Nickel(II) acetylacetonate*6.38 60 20 40 2,2-di-tert-butylphenyl phosphite 67.48 13 Nickel(II)acetylacetonate* 8.01 60 20 40 Tri-t-butylphosphine 23.89 14 Nickel(II)acetylacetonate* 6.84 60 20 40 (±)-2,2′-bis(diphenylphosphino)-1,1′-32.33 binaphthyl Comparative examples 15Bis(1,5-cyclooctadiene)nickel(0) 32.4 17 0 1101,2-bis(diphenylphosphino)ethane 57.9 16 Rhodium(II) acetate dimer, 49.720 0 110 (±)-2,2′-bis(diphenylphosphino)-1,1′- 112.1 binaphthyl*anhydrous

TABLE 2 Reaction products Reaction >Si_(n)H_((2n+2)) time DisilaneTrisilane Tetrasilane Pentasilane where n > 5 Ex. h GC % by areaAccording to the invention  1 20 74.0 21.9 4.1 0.0 0.0  2 20 75.2 20.24.6 0.0 0.0  3 2.5 78.8 18.4 2.8 0.0 0.0 67 62.2 21.8 8.7 7.3 0.0  4 2.581.4 16.2 2.4 0.0 0.0 67 46.9 23.4 15.2 9.1 5.2  5 2.5 73.7 21.1 5.2 0.00.0 67 50.4 24.6 14.5 7.8 2.8  6 2.5 73.6 21.2 5.2 0.0 0.0 67 56.2 23.312.1 6.6 1.7  7 2.5 75.8 19.6 4.5 0.0 0.0 67 49.4 25.2 14.5 7.8 3.1  82.5 66.5 25.8 7.7 0.0 0.0 67 47.8 24.3 14.8 8.5 4.6  9 1 100.0 0.0 0.00.0 0.0 20 100.0 0.0 0.0 0.0 0.0 10 1 96.6 0.0 3.4 0.0 0.0 20 69.0 23.45.7 1.8 0.0 11 1 90.6 0.0 7.0 2.4 0.0 20 66.1 28.6 4.0 1.3 0.0 12 1 56.10.0 43.9 0.0 0.0 20 39.6 45.3 8.2 6.8 0.0 13 1 100.0 0.0 0.0 0.0 0.0 2071.2 24.7 4.1 0.0 0.0 14 1 33.0 33.0 18.7 10.3 4.9 20 29.8 24.5 19.214.1 12.4 Comparative examples 15 20 0 0 0 0 0 16 20 0 0 0 0 0

The invention claimed is:
 1. A process for preparing at least one higherhydridosilane of formulaH—(SiH₂)_(n)—H, wherein n≧2, the process comprising: (A) reacting atleast one lower hydridosilane, hydrogen, and at least one transitionmetal compound comprising at least one element of transition group VIIIof the Periodic Table or the lanthanides, at a pressure of more than 5bar absolute; (B) subsequently depressurizing to give a reactionmixture; and (C) separating off the at least one higher hydridosilanefrom the reaction mixture obtained in (B).
 2. The process according toclaim 1, wherein monosilane is reacted.
 3. The process according toclaim 1, wherein a partial pressure of hydrogen corresponds to from 5%to 80% of total pressure.
 4. The process according to claim 1, whereinthe at least one transition metal is Co, Ir, Ni, Pd, Rh, or Ru.
 5. Theprocess according to claim 1, wherein the at least one transition metalcompound comprises bipyridyl, an unsubstituted or substitutedcyclopentadienyl, cyclooctadiene, CN, CO, alkylphosphine, anarylphosphine, an alkyl or aryl phosphite, alkylarylphosphine, abidentate phosphine ligand comprising a bridging heterocycle or bridgingaryl radical, a heteroatom-containing ligand, alkyldiphosphineR²R¹—P(CH_(y))_(x)P—R³R⁴ wherein R¹, R², R³ and R⁴ are each,independently of one another, alkyl or aryl and x=1-10 and y=0, 1 or 2,R²R¹—P—CR⁵R⁶(CR⁷R⁸)x-CR⁹R¹⁰—P—R³R⁴ wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷,R⁸, R⁹, R¹⁰ are each, independently of one another, H, alkyl or aryl andx=1-10; or R¹—C≡C—R², wherein R¹ and R² are each, independently of oneanother, an alkylphosphine, an arylphosphine, or a heteroatom-containingligand, as at least one ligand.
 6. The process according to claim 1,wherein the pressure is from 20 to 200 bar absolute.
 7. The processaccording to claim 1, wherein the temperature is from −50° C. to 200° C.8. The process according to claim 1, carried out in the presence of asolvent which is a constituent of a liquid phase.
 9. The processaccording to claim 2, wherein a partial pressure of hydrogen correspondsto from 5% to 80% of total pressure.
 10. The process according to claim2, wherein the at least one transition metal is Co, Ir, Ni, Pd, Rh, orRu.
 11. The process according to claim 3, wherein the at least onetransition metal is Co, Ir, Ni, Pd, Rh, or Ru.
 12. The process accordingto claim 9, wherein the at least one transition metal is Co, Ir, Ni, Pd,Rh, or Ru.
 13. The process according to claim 2, wherein the at leastone transition metal compound comprises bipyridyl, an unsubstituted orsubstituted cyclopentadienyl, cyclooctadiene, CN, CO, alkylphosphine, anarylphosphine, an alkyl or aryl phosphite, alkylarylphosphine, abidentate phosphine ligand comprising a bridging heterocycle or bridgingaryl radical, a heteroatom-containing ligand, alkyldiphosphineR²R¹—P(CH_(y))_(x)P—R³R⁴ wherein R¹, R², R³ and R⁴ are each,independently of one another, alkyl or aryl and x=1-10 and y=0, 1 or 2,R²R¹—P—CR⁵R⁶(CR⁷R⁸)x-CR⁹R¹⁰—P—R³R⁴ wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷,R⁸, R⁹, R¹⁰ are each, independently of one another, H, alkyl or aryl andx=1-10; or R¹—C≡C—R², wherein R¹ and R² are each, independently of oneanother, an alkylphosphine, an arylphosphine, or a heteroatom-containingligand, as at least one ligand.
 14. The process according to claim 3,wherein the at least one transition metal compound comprises bipyridyl,an unsubstituted or substituted cyclopentadienyl, cyclooctadiene, CN,CO, alkylphosphine, an arylphosphine, an alkyl or aryl phosphite,alkylarylphosphine, a bidentate phosphine ligand comprising a bridgingheterocycle or bridging aryl radical, a heteroatom-containing ligand,alkyldiphosphine R²R¹—P(CH_(y))_(x)P—R³R⁴ wherein R¹, R², R³ and R⁴ areeach, independently of one another, alkyl or aryl and x=1-10 and y=0, 1or 2, R²R¹—P—CR⁵R⁶(CR⁷R⁸)x-CR⁹R¹⁰—P—R³R⁴ wherein R¹, R², R³, R⁴, R⁵, R⁶,R⁷, R⁸, R⁹, R¹⁰ are each, independently of one another, H, alkyl or aryland x=1-10; or R¹—C≡C—R², wherein R¹ and R² are each, independently ofone another, an alkylphosphine, an arylphosphine, or aheteroatom-containing ligand, as at least one ligand.
 15. The processaccording to claim 9, wherein the at least one transition metal compoundcomprises bipyridyl, an unsubstituted or substituted cyclopentadienyl,cyclooctadiene, CN, CO, alkylphosphine, an arylphosphine, an alkyl oraryl phosphite, alkylarylphosphine, a bidentate phosphine ligandcomprising a bridging heterocycle or bridging aryl radical, aheteroatom-containing ligand, alkyldiphosphine R²R¹—P(CH_(y))_(x)P—R³R⁴wherein R¹, R², R³ and R⁴ are each, independently of one another, alkylor aryl and x=1-10 and y=0, 1 or 2, R²R¹—P—CR⁵R⁶(CR⁷R⁸)x-CR⁹R¹⁰—P—R³R⁴wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰ are each, independentlyof one another, H, alkyl or aryl and x=1-10; or R¹—C≡C—R², wherein R¹and R² are each, independently of one another, an alkylphosphine, anarylphosphine, or a heteroatom-containing ligand, as at least oneligand.
 16. The process according to claim 4, wherein the at least onetransition metal compound comprises bipyridyl, an unsubstituted orsubstituted cyclopentadienyl, cyclooctadiene, CN, CO, alkylphosphine, anarylphosphine, an alkyl or aryl phosphite, alkylarylphosphine, abidentate phosphine ligand comprising a bridging heterocycle or bridgingaryl radical, a heteroatom-containing ligand, alkyldiphosphineR²R¹—P(CH_(y))_(x)P—R³R⁴ wherein R¹, R², R³ and R⁴ are each,independently of one another, alkyl or aryl and x=1-10 and y=0, 1 or 2,R²R¹—P—CR⁵R⁶(CR⁷R⁸)x-CR⁹R¹⁰—P—R³R⁴ wherein R¹, R², R³, R⁴, R⁵, R⁶, R⁷,R⁸, R⁹, R¹⁰ are each, independently of one another, H, alkyl or aryl andx=1-10; or R¹—C≡C—R², wherein R¹ and R² are each, independently of oneanother, an alkylphosphine, an arylphosphine, or a heteroatom-containingligand, as at least one ligand.
 17. The process according to claim 10,wherein the at least one transition metal compound comprises bipyridyl,an unsubstituted or substituted cyclopentadienyl, cyclooctadiene, CN,CO, alkylphosphine, an arylphosphine, an alkyl or aryl phosphite,alkylarylphosphine, a bidentate phosphine ligand comprising a bridgingheterocycle or bridging aryl radical, a heteroatom-containing ligand,alkyldiphosphine R²R¹—P(CH_(y))_(x)P—R³, R⁴ wherein R¹, R², R³ and R⁴are each, independently of one another, alkyl or aryl and x=1-10 andy=0, 1 or 2, R²R¹—P—CR⁵R⁶(CR⁷R⁸)x-CR⁹R¹⁰—P—R³R⁴ wherein R¹, R², R³, R⁴,R⁵, R⁶, R⁷, R⁸, R⁹, R¹⁰ are each, independently of one another, H, alkylor aryl and x=1-10; or R¹—C≡C—R², wherein R¹ and R² are each,independently of one another, an alkylphosphine, an arylphosphine, or aheteroatom-containing ligand, as at least one ligand.
 18. The process ofclaim 1, wherein the at least one transition metal comprises at leastone phosphorus-containing ligand, which produces atropisomerism inrespect of two aryl or hetaryl systems, as a ligand.